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quest · builder's guild

Marble Run Wall

Cardboard tubes. Tape. One wall. Gravity does the rest. This is real engineering — every joint has to line up.

Grab a grown-upIntermediate1 hour🏠 Indoors

A grown-up works with you and owns a few steps of this quest.

🧑 The grown-up owns: Does all cutting, approves the wall/tape, and keeps marbles away from little kids and pets.

what you'll need

  • 6+ cardboard tubes (paper towel / toilet paper)
  • Painter's tape (won't peel paint)
  • A marble
  • A cup or bowl at the bottom

safety · Marbles are a choking hazard: no little kids or pets in the room, and every marble goes back in a closed container the second you're done. All cutting is done by a grown-up — no scissors, blades, or box cutters in this build. Never stand on furniture to reach higher; build only as high as your own arms.

🧑 grown-up does

These steps belong to the grown-up. Grab a grown-up.

  1. 1. Approve the wall and the tape

    Pick a surface that painter's tape won't damage — a fridge side, a closet door, or a big cardboard box.

  2. 2. Do all the cutting

    Slice the tubes in half lengthwise into open troughs. Trim the ends square. Hand back finished pieces so no blade goes near the Sk8er.

  3. 3. Own the marbles

    Keep the marbles until build time, keep small children and pets out of the room, and collect every marble at the end.

Read the safety badge and the grown-up steps together before you start.